External Validation of the COVID-NoLab and COVID-SimpleLab Prognostic Tools

Article Figures & Data

Table 1.

COVID-NoLab and COVID-SimpleLab Risk Scores

Risk Score and Components	Points
COVID-NoLaba
Age group
50-65 y	3
≥66 y	5
Respiratory rate ≥30	3
Oxygen saturation <93%	2
COVID-SimpleLabb
C-reactive protein level >10 mg/dL	5
Respiratory rate ≥30	5
Oxygen saturation <93%	4
Age group
50-65 y	6
≥66 y	8
Asthma	4
White blood cell count >10 × 10⁹/mL	3
Serum creatinine level >2.0 mg/dL	4

a Score range is 0 to 10 points. Risk groups: low (0-1 point), moderate (2-5 points), high (≥6 points).
b Score range is 0 to 33 points. Risk groups: low (0-7 points), moderate (8-11 points), high (≥12 points).

Table 2.

Comparison of Predicted Mortality Between Original Derivation Cohort and Quebec Validation Cohort

Risk Group^{^a}	Original Derivation Cohort^{^b}			Quebec Validation Cohort^{^c}			P Value^{^d}
Risk Group^{^a}	Patients, %	Mortality Rate, % (95% CI)	SSLR	Patients, %	Mortality Rate, % (95% CI)	SSLR	P Value^{^d}
COVID-NoLab
Low	22	1.3 (0.4-3.4)	0.10	16	1.1 (0.02-5.7)	0.10	.83
Moderate	67	11.3 (9.4-13.4)	0.93	64	9.6 (6.8-13.0)	0.91	.36
High	11	30.5 (24.4-37.0)	3.20	20	21.2 (14.2-30.0)	2.00	.07
COVID-SimpleLab
Low	31	0.4 (0.01-2.4)	0.03	26	0.0 (0.0-2.8)	0.00	.46
Moderate	31	8.3 (5.0-12.6)	0.60	34	9.8 (5.7-15.5)	0.87	.59
High	38	30.6 (25.3-36.4)	2.20	40	20.0 (14.6-26.4)	1.80	.01

SSLR = stratum-specific likelihood ratio.
↵a See Table 1 for cutoffs for the risk groups.
↵b Cohort had 1,527 patients for the COVID-NoLab risk score and 740 patients for the COVID-SimpleLab risk score.
↵c Cohort had 588 patients for the COVID-NoLab risk score and 479 patients for the COVID-SimpleLab risk score.
↵d From the Pearson χ² test for the comparison of mortality rates between cohorts.